/Engine/Source/Runtime/CoreOnline/Public/Online/CoreOnline.h
Register a registry for a given OnlineServices implementation and IOnlineAccountIdHandle type
void RegisterAccountIdRegistry ( [EOnlineServices](API\Runtime\CoreOnline\Online\UE__Online__EOnlineServices) OnlineServices, [IOnlineAccountIdRegistry](API\Runtime\CoreOnline\Online\IOnlineAccountIdRegistry) * Registry, int32 Priority )